Reservoir for hybrid scba

Abstract

A SCBA with an air storage, a face piece with inner mask (nose cup), breathing regulator(s), a breathing valve, an exhalation valve operating at positive pressure relative to the ambient and a reservoir capable of storing the first part of an exhalation and delivering that part at the subsequent inhalation. The reservoir is positioned in the SCBA's face piece or in close proximity thereto, is in fluid contact with the inner mask, and has a shut-off valve controlled by a carbon-dioxide sensor. The operating pressure of the reservoir is maintained above ambient pressure and the operating pressure of the reservoir is between the opening pressure of the SCBA's breathing valve and the SCBA's exhalation valve.

1 . A SCBA comprising a source of pressurized breathing gas, a face piece with inner mask (nose cup), breathing regulator(s), an exhalation valve operating at positive pressure relative to the ambient and a reservoir capable of storing the first part of an exhalation and delivering that part at the subsequent inhalation, wherein said reservoir specifically:
 is positioned in the SCBA's face piece or in close proximity thereto,   is in fluid contact with and in close proximity to the inner mask, and   has a shut-off valve controlled by a carbon-dioxide sensor, and wherein   the operating pressure of the reservoir is controlled to be above ambient pressure; and   the operating pressure of the reservoir is controlled to be between the opening pressures of the breathing valve and the exhalation valve.   
     
     
         2 . The SCBA of  claim 1  wherein the carbon-dioxide sensor is positioned in the inlet of the reservoir, and wherein the shut-off valve is operated to close the reservoir when the carbon dioxide content of the exhalation has reached a predetermined value, and wherein a latter portion of an exhalation is discharged to the ambient via the exhalation valve. 
     
     
         3 . The SCBA of  claim 1  wherein the carbon-dioxide sensor is positioned inside the reservoir. and wherein the shut-off valve is operated to close the reservoir when the carbon dioxide content of the exhalation reaches levels too dangerous to be re-breathed and wherein a latter portion of an exhalation is discharged to the ambient via the exhalation valve.